The Jabba's Palace musical scene was god-awful to begin with. It became even worse in the Special Editions, but the moment they thought a BLUE ELEPHANT was a cool idea for an alien, it was already worthless.
The Jabba scene doesn't add anything, but as he's referenced throughout A New Hope and Empire, it makes sense to have him in there. It's a push, for me.
I can't explain the Vader's ship thing landing either, unless it was to show people that he was not on the Star Destroyer and not still on Cloud City. I knew what was going on when I was a kid, so who knows what morons this is supposed to be for.
I can't believe even the most die-hard traditionalist wouldn't be in favor of putting McDiarmid in Empire. It makes NO sense for the guy to play him in three films BEFORE Empire and one film after Empire and not be the same guy. It looks so much better and uniform now, and I thought the change of dialogue was a nice touch.
I think the Ewoks are crap, so changing the celebration at the end is fine with me. While the new Williams music is a little new agey, it's a much more dignified end to the saga than the fucking Yub Yub song. Also, showing the reaction on different worlds is appropriate considering the scope of the whole thing. As for the replacing of Anakin's ghost with the image of Hayden, it's pretty obvious to me. This is meant to be a 6 film saga now, and if it's about the rise and fall and redemption of Anakin Skywalker, it makes more emotional sense to have him at the end instead of some old guy who's barely recognizable as the guy under Vader's mask to begin with. He didn't have any lines as a ghost, so it's not like they robbed the actor of anything; he still has a nicely played death scene with Luke. But if you consider that Anakin lost his soul when he went over to the dark side, it makes sense that in death he is returned back to the way he was when he was still good. I think it's going to mean a lot more to future generations who watch this thing. But hey, why think like that when you can selfishly act like the films were all made for you and your generation only? Part of Lucas' gift is crafting a story and characters that are timeless and universal, which is why in 20 years no one's going to give a shit about The Matrix and its whole leather trenchcoat and sunglasses fashion bullshit.
Last, the things that are most important to me are the Biggs scene (there's still more material that wasn't put back in, damnit!) and the fleshing out of Mos Eisley and Cloud City. I agree with you, Elevated, that there is too much digital clutter in those scenes, like the Jawa swinging from the Bantha, but I can live with that when I get to see something as sprawling as it was originally imagined by Lucas, and described by Obi-Wan. The Falcon's approach to Cloud City is awesome, and makes the location worthy of what's in the prequels, plus making the walls transparent during the later scenes so you could see the city outside really makes it more legitimate.